William Cookworthy, found the China Clay in Cornwall

William Cooksworthy found China Clay in Cornwall, and developed
a way to process it into fine porcelain pieces.

The St Austell
deposits have now been worked for over 200 years and are the largest in
the world. Around 120 million tons of china clay have been produced since William
Cookworthy's first discovered it at Tregonning Hill in 1746, but reserves are
sufficient for at least another hundred years.

William Cookworthy was born in 1705 and he was the son of a Quaker weaver
from Kingsbridge in Devon. His father died in 1718 and the family were quickly
reduced to a state of poverty.He became an apprentice to Silvanus Bevan, a Quaker
chemist and druggist in London. William was so poor that he could not afford
the coach fare from Devon to London, and had to walk the whole 200 miles.

In 1726, Bevan decided to start a wholesale pharmacy business in Notte Street,
Plymouth, and William took a job there. By 1735 Cooksworthy and Bevan were partners.
In that year he married Miss Sarah Berry. Ten years later he bought out his
partners but Sarah’s unexpected death that year left him with a family
of five girls to bring up on his own. His brother, Philip, joined him as a partner
and the business became Messrs William Cookworthy and Company, the Bevans having
by now left the scene.

The Cookworthys' apothecary shop,continued as a pharmacy until 1974 when the
last proprietor retired. The business flourished, supplying merchant ships in
the busy port. He is said to have entertained Captain Cook and Joseph Banks
before they sailed in Endeavour to Otaheite, in the Pacific Ocean, in 1769.

William Cookworthy happened to read a description of Chinese porcelain manufacture
written by a Jesuit missionary in the 1740s. This accidental find, aroused his
curiosity, which was further enhanced when he was visited by businessmen from
Virginia with samples of Virginian clay and porcelain in 1745.

They wanted him to import Virginian clay and make porcelain in England. Cookworthy
decided to look for these minerals in England, and he found them locally in
Cornwall. They were known as Moorstone or Growan, and Growan clay. Cookworthy
began to experiment with these ingredients. However, it took him until 1768
to file a patent specification, and be granted Patent number 898 for "Making
porcelain from Moorstone, Growan and Growan clay."

At that point in time, English potters were only able to produce what was known
as ‘earthenware’. Porcelain was imported from China, where the clay
used was known as ‘kaolin’. But in 1746 Cookworthy discovered china
clay at Tregonning Hill in Germo Parish, Cornwall, where it was known as “moorstone”.
He noticed miners repairing the furnaces with clay at the
Great Work Mine, and found out where they were getting it from. Having found
that it was suitable for making porcelain, he leased some clay pits on the Hill.
He shipped the clay from Porthleven to Plymouth, where he determined the best
way to turn it into porcelain. By December 1766 he had set up a small factory.

The clay from Tregonning Hill however contained dark specks of mica, which
detracted from a top quality finished product. Better quality clay was found
on land owned by Mr Thomas Pitt in St Stephen’s, near St Austell. Mr Pitt,
who was to become Lord Camelford in 1784, invested money in the process and
became a partner with him in the Plymouth China Works in Plymouth.

They primarily made decorated tea services, jugs and vases. However, the business
was not making a profit in Plymouth, and it amalgamated with a pottery in Bristol.
Cookworthy made his cousin, Richard Champion, his manager of "William Cookworthy
and Company." In 1774, Cookworthy sold his interest in the business and
patent to Champion. Champion continued to buy the ingredients for the porcelain
from Camelford, and paid a royalty to Cookworthy.

When Richard Champion tried to renew Cookworthy’s patent
in 1777, Josiah Wedgwood and other potters in Staffordshire raised objections.
The patent formula was upheld, but the actual use of the china clay was released
so that ceramic products could be made from it provided that the formula was
not infringed. The cost of the legal battle crippled the Company and Richard
sold the formula in 1782 to the New Hall Porcelain Company, which had been formed
by the Staffordshire potters. They continued to produce porcelain until around
1810, when bone china became available.

William Cookworthy died on Tuesday October 17th 1780 and was buried
in the family vault in the Westwell Street Burial Ground. At that time the wholesale
business in Notte Street passed to his young brother, Benjamin.

The earliest known extant piece of Cookworthy's hard-paste porcelain is now
in the British Museum; a blue decorated mug bearing the Arms of Plymouth and
the inscription "14 March 1768 C.F." - presumably the initials mean
"Cookworthy fecit" (made it).